1. Field of the Invention
This invention relates generally to control devices having pawl regulated actuators and is concerned more particularly with an electrical switch having a reciprocally movable actuator regulated by a continuously controlled pawl.
2. Discussion of the Prior Art
There has been developed in the prior art an electrical switch having a pushbutton actuator provided with a shaft driven plunger which is disposed for reciprocal movement in a switch housing. The plunger is spring-biased to return, when released, toward a position of maximum shaft extension from the housing where the switch is disposed in a first operating condition. Within the housing, the plunger carries a pawl which is rotated when the plunger is pressed fully into the housing and released. The orientation of the pawl determines whether the plunger will return to the position of maximum shaft extension or be locked in a position of partial shaft extension where the switch is disposed in a second operating condition.
In accordance with design strategy, the plunger is pressed from its position of maximum shaft extension and fully into the housing where it is then released. As a result, the pawl should be rotated in a predetermined direction to orient it properly for locking the returning plunger in the position of partial shaft extension and disposing the switch in the second operating condition. Subsequently, the plunger is pressed from its position of partial shaft extension and fully into the housing where it is released again. Consequently, the pawl should be rotated in the same predetermined direction to orient it properly for permitting the returning plunger to travel to its position of maximum shaft extension and disposing the switch in the first operating condition. Thus, in accordance with design strategy, the first and second operating conditions of the switch should occur sequentially, even when it is necessary to return to one of the operating conditions of the switch. Because of its sequential operation, this type of electrical switch generally is referred to as a "push-to-lock; push-to-release" switch.
However, in practice, it may be found that the described electrical switch is not always disposable in the first and second operating conditions sequentially. While the plunger is travelling fully into the housing and while returning therefrom, the pawl carried on the plunger is freely rotatable in either the aforesaid predetermined direction or in the reverse direction. Consequently, during these intervals of operation, the pawl may spin backward in said reverse direction and be improperly oriented for producing the expected sequential operating condition of the switch. As a result, the switch will not be disposed in the correct operating condition for obtaining a desired electrical result from connecting electrical circuitry.